Who Painted the Fall Leaves?!
Lila and Koko discover why green leaves transform into autumn's brightest colors.
Read along
Every autumn, green leaves seem to turn yellow, orange, and red overnight. But no one painted them. During spring and summer, leaves are full of chlorophyll, the green material that helps plants use sunlight to make food. When days get shorter and cooler, trees stop making as much chlorophyll. As the green fades, yellow and orange colors that were hiding inside the leaf become visible. Some trees also make red pigments when sugar gets trapped in their leaves. Weather, tree type, and daylight all help decide the final color show. Then the tree drops its leaves and saves energy for winter.
Inside the story
Scene by scene
Pause, look closer, and discover the science behind each part of the adventure.
Scene 0101
Green at work
“All summer long, green leaves work like tiny kitchens, using sunlight to make food for the tree.”
Chlorophyll absorbs light energy for photosynthesis. It reflects green wavelengths, which is why healthy summer leaves look green.
Scene 0202
Hidden colors appear
“As autumn days shrink, the green color fades and bright yellows and oranges finally get their turn to shine.”
Yellow and orange carotenoid pigments were present all along. We notice them only after the leaf stops replacing its chlorophyll.
Scene 0303
A winter rest
“The color show ends with a flutter. Leaves fall, and the tree settles in to save water and energy for winter.”
A thin layer of cells forms where the leaf meets the branch. It eventually seals the branch and lets the leaf drop safely.
Keep wondering